You could simply get yourself in short range of the opponent and engage in a taijutsu fight, where as the opponent would be distracted and his main focus would be to out maneuver your moves. You can simply almost glue it onto their body without them being able to recognise.
Retrieving a bomb tag which I keep hidden from my opponent due to creating an element of surprise, I sprint in their direction and upon reaching close range, I place the tag near the chest portion of the opponent and then without any further delay, I withdraw from my original position and within the same motion watch as it detonates.
Retrieving a bomb tag which I keep hidden from my opponent due to creating an element of surprise, I sprint in their direction and upon reaching close range, I place the tag near the chest portion of the opponent and then without any further delay, I withdraw from my original position and within the same motion watch as it detonates.